Plant root hairs are commonly found artifacts in parasitology specimens and may be confused with helminthes by an untrained eye. We report a case of brain tuberculoma where the tissue sample was contaminated with root hair derived from tap water; the presence of this root hair, which mimicked a larva, led to diagnostic confusion. Therefore, tap water should be considered a source of root hair and vegetable matter.
Animals ; Brain Diseases/*diagnosis/pathology ; *Diagnostic Errors ; Helminthiasis/diagnosis ; Helminths/growth & development ; Humans ; Larva/anatomy & histology ; Male ; Middle Aged ; Plant Roots/*anatomy & histology ; Tomography, X-Ray Computed ; Tuberculoma/*diagnosis/pathology ; Water

The present study was performed to describe 2 human cases infected by the horsehair worm, Parachordodes sp., in Japan. Two gordiid worms were collected in the vomit and excreta of an 80-year-old woman in November 2009 in Kyoto city, and in the mouth of 1-year-old boy in December 2009 in Nara city, Japan, respectively. Both worms were males having bifurcated posterior ends and male gonads in cross sectional specimens. They were identified as Parachordodes sp. (Nematomorpha: Chordodidae) based on the characteristic morphologies of cross sections and areoles in the cuticle. DNA analysis on 18S rRNA partial sequence arrangements was also carried out and both worms were assumed to be close to the genus Paragordionus based on tree analysis, and far from Gordius sp. which has already been reported in humans in Japan. DNA sequencing of the Parachordodes worm does not appear on the database; therefore, more information on the gene sequences of the genus Parachordodes from humans, animals, or intermediates is required.
Aged, 80 and over ; Animals ; Cluster Analysis ; DNA, Helminth/chemistry/genetics ; DNA, Ribosomal/chemistry/genetics ; Female ; Helminthiasis/*diagnosis/*parasitology/pathology ; Helminths/anatomy & histology/classification/genetics/*isolation & purification ; Humans ; Infant ; Japan ; Male ; Microscopy ; Phylogeny ; RNA, Ribosomal, 18S/genetics ; Sequence Analysis, DNA